1. Field of the Invention
The invention relates to a semiconductor device and a method for fabricating the same, and particularly relates to an oxide semiconductor device and a method for fabricating the same.
2. Description of Related Art
Recently, since an oxide semiconductor (OS) device has higher carrier mobility, a more stable threshold voltage (Vth), and suitable for large-area fabrication compared to the traditional amorphous silicon (a-Si), the oxide semiconductor device has been already applied to the display plates generally.
However, in a fabrication of the traditional oxide semiconductor device, a source and a drain are usually formed first, and then a conductive material is filled in a space between the source and the drain to form a gate, and forming a multi-layer oxide semiconductor layer is needed. Therefore, steps of fabrication are complicated. Besides, since a depth of the space is deeper between the source and the drain, the conductive material as the gate is not filled therein easily. Thus, voids or holes are easily generated in the fabrication to influence the performance of the device.